Motorized bicycle derailleur assembly

ABSTRACT

A motorized bicycle front derailleur assembly is provided that includes a motor unit, a front derailleur and a motor linkage. The motor unit is configured to rotate an output shaft in first and second opposite rotational directions. The front derailleur includes a fixing body configured to be mounted to a bicycle frame, inner and outer links pivotally coupled to the fixing body at first and second pivot points, and a chain guide pivotally coupled to the inner and outer links to move between an inner shift position and an outer shift position. The first pivot point is located laterally closer to a center plane of the bicycle frame than the second pivot point. The motor linkage is operatively coupled to the output shaft of the motor unit and the inner link to move the chain guide between the inner and outer shift positions upon rotation of the output shaft.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention generally relates to a motorized bicycle derailleurassembly. More specifically, the present invention relates to amotorized bicycle front derailleur assembly with a drive link coupled toan inner link to move the chain guide laterally outwardly when a pullingforce is applied to the inner link.

2. Background Information

Bicycling is becoming an increasingly more popular form of recreation aswell as a means of transportation. Moreover, bicycling has become a verypopular competitive sport for both amateurs and professionals. Whetherthe bicycle is used for recreation, transportation or competition, thebicycle industry is constantly improving the various components of thebicycle. In fact, bicycles have recently been equipped with electricalcomponents to make riding easier and more enjoyable for the rider. Somebicycles are equipped with automatic shifting units that areautomatically adjusted according to the riding conditions by a cyclecomputer or control unit. In particular, the front and rear derailleurshave recently been automated.

Generally speaking, the front derailleur is secured to the seat tube ofthe bicycle frame or the bottom bracket, while the rear derailleur issecured to the rear triangle of the frame. In either case, a derailleurincludes a fixed or base member non-movably secured to a bicycle frame,and a movable member supported to be movable relative to the fixedmember via a linkage. The movable member typically has a chain guidewith a pair of cage plates for moving a chain between the front or rearsprockets. The movable member is usually biased in a given directionrelative to the fixed member by a spring. The movable member is usuallymoved relative to the fixed member by pulling and/or releasing a shiftcontrol cable that is coupled to the respective derailleur. In amanually operated derailleur, a control cable is connected to one of thepivotal links to apply a torque thereto, thereby causing the links tomove the movable member. The control cable is fixed to the link in aposition such that an operating force applied to the control cable isconverted into a link swinging torque. The movement of the control cableis typically controlled by a shift operating device that has one or morelevers, a winding member and in indexing mechanism in a conventionalmanner.

In recent years, derailleurs have been motorized. In a motorizedderailleur, a motor is typically used to pull and release a controlcable to move the movable member, or the motor is connected by a drivetrain (transmission) to the derailleur without a conventional controlcable to move the movable member. In either case, the motor is typicallyan electric motor that is operatively coupled to a control unit. Thecontrol unit can automatically control the motor, and thus,automatically control movement of the movable member of the derailleur.Alternatively, electrical shift buttons can be provided, which areoperatively coupled to the control unit such that the rider can controlthe shifting of the derailleur.

While these prior motorized derailleurs work relatively well, they dosuffer from some deficiencies. In particular, these prior motorizedderailleurs do not always operate as reliably as desired by some riders.Moreover, these prior motorized derailleurs are not always as easilyadjusted as desired by some riders. Furthermore, these prior derailleursare not always as simple and inexpensive to manufacture and assemble asdesired. Finally, these prior motorized derailleurs often have a motorunit assembly, which requires numerous fasteners to couple the partstogether, which can be relatively complicated.

It will be apparent to those skilled in the art from this disclosurethat there exists a need for an improved motorized bicycle derailleurassembly. This invention addresses this need in the art as well as otherneeds, which will become apparent to those skilled in the art from thisdisclosure.

SUMMARY OF THE INVENTION

One object of the present invention is to provide a motorized bicyclefront derailleur assembly, which is reliable.

Another object of the present invention is to provide a motorizedbicycle front derailleur assembly that is configured and arranged to beeasily adjusted.

Another object of the present invention is to provide a motorizedbicycle front derailleur assembly that includes a jamming protectionconnection.

Yet another object of the present invention is to provide a motorizedbicycle front derailleur assembly that is relatively simple andinexpensive to manufacture and assemble.

The foregoing objects can basically be attained by providing a motorizedbicycle front derailleur assembly that includes a motor unit, a frontderailleur and a motor linkage. The motor unit is configured andarranged to rotate an output shaft in a first rotational direction and asecond rotational direction that is opposite the first rotationaldirection. The front derailleur includes a fixing body configured to bemounted to a bicycle frame, an inner link pivotally coupled to thefixing body at a first pivot point, an outer link pivotally coupled tothe fixing body at a second pivot point and a chain guide pivotallycoupled to the inner and outer links to move between an inner shiftposition and an outer shift position. The first pivot point is locatedlaterally closer to a center plane of the bicycle frame than the secondpivot point. The motor linkage is operatively coupled to the outputshaft of the motor unit and the inner link of the front derailleur tomove the chain guide from the inner shift position to the outer shiftposition upon rotation of the output shaft in the first rotationaldirection and to move the chain guide from the outer shift position tothe inner shift position upon rotation of the output shaft in the secondrotational direction.

These and other objects, features, aspects and advantages of the presentinvention will become apparent to those skilled in the art from thefollowing detailed description, which, taken in conjunction with theannexed drawings, discloses a preferred embodiment of the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the attached drawings which form a part of thisoriginal disclosure:

FIG. 1 is a side elevational view of a bicycle equipped with a motorizedfront derailleur assembly in accordance with the present invention;

FIG. 2 is an enlarged outer side elevational view of the motorized frontderailleur assembly illustrated in FIG. 1 with the chain guide in a lowshift position, and with the motor unit cover removed for the purpose ofillustration;

FIG. 3 is a front elevational view of the motorized front derailleurassembly illustrated in FIG. 2 with the chain guide in the low shiftposition;

FIG. 4 is a rear elevational view of the motorized front derailleurassembly illustrated in FIGS. 2 and 3 with the chain guide in the lowposition, and with the motor unit cover coupled thereto;

FIG. 5 is an inner side elevational view of the motorized frontderailleurs assembly illustrated in FIGS. 2-4, with the motor unit andportions of the motor linkage removed for the purpose of illustration;

FIG. 6 is a partial cross-sectional view of the motorized frontderailleur assembly illustrated in FIGS. 2-5, as seen along section line6-6 of FIG. 5;

FIG. 7 is a further enlarged, partial rear elevational view of themotorized front derailleur assembly illustrated in FIGS. 2-4 with thechain guide in the low position, and with the motor unit cover removedfor the purpose of illustration;

FIG. 8 is a rear elevational view of the motorized front derailleurassembly illustrated in FIGS. 2-4 with the chain guide in the topposition;

FIG. 9 is a further enlarged, rear elevational view of the motorizedfront derailleur assembly illustrated in FIG. 8 with the chain guide inthe top position, and with the motor unit cover removed for the purposeof illustration;

FIG. 10 is a rear elevational view of the portion of the motorized rearderailleur assembly illustrated in FIG. 9, with portions broken away andportions illustrated in cross-section for the purpose of illustration ofthe jamming protection connection;

FIG. 11 is a partial, rear elevational view of the motorized frontderailleur assembly illustrated in FIGS. 2-10 having the motor linkagemoved into the low position/orientation and the derailleur linkage beingheld such that the chain guide remains in the top position (e.g. from ajam or the like);

FIG. 12 is a rear, perspective view of the motorized front derailleurassembly illustrated in FIGS. 2-11, with the chain guide in the lowposition and with the motor unit cover removed for the purpose ofillustration, and with portions illustrated as simplified shapes (e.g.the drive link and the saver link) for the purpose of illustration;

FIG. 13 is a rear, perspective view of the motorized front derailleurassembly illustrated in FIGS. 2-11, with the chain guide in the topposition and with the motor unit cover removed for the purpose ofillustration, and with portions illustrated as simplified shapes (e.g.the drive link and the saver link) for the purpose of illustration;

FIG. 14 is an enlarged, exploded perspective view of the inner link andsaver link assembly (i.e. the jamming protection connection) of themotorized front derailleur assembly illustrated in FIGS. 2-13;

FIG. 15 is a perspective view of the inner link and saver link assembly(i.e. the jamming protection connection) illustrated in FIG. 14, in theassembled state;

FIG. 16 is an enlarged, partial rear elevational (diagrammatic) view ofthe mechanical adjustment device of the motorized front derailleurassembly illustrated in FIGS. 2-13, with the chain guide in the lowposition;

FIG. 17 is an enlarged, partial rear elevational (diagrammatic) view ofthe mechanical adjustment device of the motorized front derailleurassembly illustrated in FIGS. 2-13, with the chain guide in the topposition;

FIG. 18 is an enlarged rear perspective view of the a first housing partof the motor unit housing of the motorized front derailleur assemblyillustrated in FIGS. 2-13;

FIG. 19 is an outer side elevational view of the first housing partillustrated in FIG. 18;

FIG. 20 is a front elevational view of the first housing partillustrated in FIGS. 18 and 19;

FIG. 21 is an enlarged front perspective view of the a second housingpart of the motor unit housing of the motorized front derailleurassembly illustrated in FIGS. 2-13;

FIG. 22 is an inner side elevational view of the second housing partillustrated in FIG. 21;

FIG. 23 is a front elevational view of the second housing partillustrated in FIGS. 21 and 22;

FIG. 24 is a top plan view of the second housing part illustrated inFIGS. 21-23;

FIG. 25 is an enlarged front perspective view of the motorized frontderailleur mounting member of the motorized front derailleur assemblyillustrated in FIGS. 2-13;

FIG. 26 is a top plan view of the motorized front derailleur mountingmember illustrated in FIG. 25;

FIG. 27 is a rear elevational view of the motorized front derailleurmounting member illustrated in FIGS. 25 and 26;

FIG. 28 is an outer side elevational view of the motorized frontderailleur mounting member illustrated in FIGS. 25-27;

FIG. 29 is an enlarged rear perspective view of the motor unit cover(i.e. a secondary motor unit mounting portion) of the motorized frontderailleur assembly illustrated in FIGS. 2-13;

FIG. 30 is a rear elevational view of the motor unit cover illustratedin FIG. 29;

FIG. 31 is an outer side elevational view of the motor unit coverillustrated in FIGS. 29 and 30;

FIG. 32 is a front elevational view of the motor unit cover illustratedin FIGS. 29-31;

FIG. 33 is an enlarged rear perspective view of the inner link of themotorized front derailleur assembly illustrated in FIGS. 2-13;

FIG. 34 is a bottom plan view of the inner link illustrated in FIG. 33;

FIG. 35 is an inner side elevational view of the inner link illustratedin FIGS. 33 and 34;

FIG. 36 is a rear elevational view of the inner link illustrated inFIGS. 33-35;

FIG. 37 is an enlarged rear perspective view of the outer link of themotorized front derailleur assembly illustrated in FIGS. 2-13;

FIG. 38 is an outer side elevational view of the outer link illustratedin FIG. 37;

FIG. 39 is a cross-sectional view of the outer link illustrated in FIGS.37 and 38, as seen along section line 39-39 of FIG. 38;

FIG. 40 is an inner side elevational view of the outer link illustratedin FIGS. 37-39;

FIG. 41 is an enlarged front perspective view of the saver link of themotorized front derailleur assembly illustrated in FIGS. 2-13;

FIG. 42 is a front elevational view of the saver link illustrated inFIG. 41;

FIG. 43 is a cross-sectional view of the saver link illustrated in FIGS.41 and 42, as seen along section line 43-43 of FIG. 42;

FIG. 44 is an inner side elevational view of the saver link illustratedin FIGS. 41-43;

FIG. 45 is a rear elevational view of the drive link of the motorlinkage of the motorized front derailleur assembly illustrated in FIGS.2-13;

FIG. 46 is an inner side elevational view of the biasing element of thejamming protection connection of the motorized front derailleur assemblyillustrated in FIGS. 2-13;

FIG. 47 is a rear elevational view of the biasing element illustrated inFIG. 46, showing the biasing element in the loaded (e.g. installed,deformed) state, and with the unloaded (e.g. pre-installed,pre-deformed) shape shown in phantom lines for the purpose ofillustration;

FIG. 48 is a rear elevational view of the drive arm of the output shaftof the motorized front derailleur assembly illustrated in FIGS. 2-13;

FIG. 49 is a cross-sectional view of the drive arm illustrated in FIG.48, as seen along section line 49-49 of FIG. 48;

FIG. 50 is a side elevational view of the drive pin (i.e. eccentric pin)of the output shaft of the motorized front derailleur assemblyillustrated in FIGS. 2-13;

FIG. 51 is an enlarged front elevational view of the motor unit of themotorized front derailleur assembly illustrated in FIGS. 2-13; and

FIG. 52 is an enlarged side elevational view of the motor unit and themotorized front derailleur mounting member of the motorized frontderailleur assembly illustrated in FIGS. 2-13 prior to coupling theseparts together via first and second fastener-less mating structures.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A selected embodiment of the present invention will now be explainedwith reference to the drawings. It will be apparent to those skilled inthe art from this disclosure that the following descriptions of theembodiment of the present invention are provided for illustration onlyand not for the purpose of limiting the invention as defined by theappended claims and their equivalents.

Referring initially to FIGS. 1-4, a bicycle 10 is illustrated that isequipped with a motorized bicycle front derailleur assembly 12 inaccordance with a first embodiment of the present invention. The bicycle10 includes a bicycle frame 14 having a seat tube 16 with the motorizedfront derailleur assembly 12 mounted to the seat tube 16 by a bracket 18and a plurality of fasteners or bolts 19, as best seen in FIGS. 2-4. Thefront derailleur assembly 12 is actuated/operated in a conventionalmanner by an electronic shifting unit 20 coupled to a front electricalshift control device 22 a via an electric shift cable to move a chain 24between at least two front sprockets or chain wheels 26 and 28.

The sprockets 26 and 28 are part of a bicycle drive train that includesa rear electrical shift control device 22 b as well as various otherconventional parts such as pedals, a crank set, one or more rearsprockets, a motorized rear derailleur, a freewheel and the chain 24.The electrical shift control device 22 a is preferably provided with apair of shift buttons (not shown) that are operatively coupled to theelectronic shifting unit 20, preferably in accordance with U.S. Pat. No.6,073,730 (assigned to Shimano, Inc.) and U.S. Pat. No. 6,682,087(assigned to Shimano, Inc.). The electrical shift control device 22 a isbasically a mirror image of the shift control device 22 b, and islocated on the opposite side of the handlebar from the shift controldevice 22 b. Thus, the shift control device 22 a is located behind (i.e.is hidden behind) the shift control device 22 b in FIG. 1.

Since the majority of the parts of the bicycle 10 are well known in thebicycle art, these parts will not be discussed or illustrated in detailherein, except as they are modified to be used in conjunction with thepresent invention. Moreover, various conventional bicycle parts, whichare not illustrated and/or discussed herein, can also be used inconjunction with the present invention.

Referring now to FIGS. 2-13, the motorized front derailleur assembly 12basically includes a motorized front derailleur unit 30, a motorizedfront derailleur mounting member 32, a front derailleur motor unit 34and a motor linkage 36. The motorized front derailleur unit 30, thefront derailleur motor unit 34 and the motor linkage 36 are all mountedon the motorized front derailleur mounting member 32. The motorizedfront derailleur mounting member 32 is configured and arranged tofixedly couple the motorized front derailleur assembly 12 to the seattube 16 of the bicycle frame 14 via the bracket 18 and the fasteners 19.

As explained in more detail below, the motorized front derailleurassembly 12 is constructed to move between at least a low shift positionas illustrated in FIGS. 2-7 and 12 and a top shift position asillustrated in FIGS. 8-10 and 13. Moreover, as illustrated in FIG. 11,the motor linkage 36 is designed with a derailleur protectionarrangement (i.e. a jamming protection connection) such that thederailleur motor unit 34 can be operated even though the motorized frontderailleur unit 30 does not move (e.g. becomes jammed). The basicoperation of shifting the chain 24 is relatively conventional, and thus,will not be discussed and/or illustrated in detail herein.

As best seen in FIGS. 2-13, the front derailleur unit 30 basicallyincludes a chain guide 40, a derailleur linkage 42 and a fixing body 44that is part of the mounting member 32, as explained below. Thederailleur linkage 42 together with the chain guide 40 and the fixingbody 44 preferably form a four-bar linkage that controls the lateralmovement of the chain guide 40. The derailleur linkage 42 is operativelycoupled between the fixing body 44 and the chain guide 40 for lateralmovement of the chain guide 40 relative to the fixing body 44 between atleast a low shift position and a top shift position, i.e., at leastfirst and second shift positions. More specifically, the chain guide 40is movably coupled to the fixing body 44 by the derailleur linkage 42,which is operatively coupled to the motor linkage 36 to move the chainguide 40 between the first and second shift positions in response tooperation of front derailleur motor unit 34. This lateral movement ofthe chain guide 40 causes the chain 24 to be shifted between thesprockets 26 and 28 of the bicycle drive train 24.

The chain guide 40 is preferably constructed of a hard rigid material.For example, the chain guide 40 is preferably constructed of a metalmaterial such as a rigid sheet metal that is bent to the desired shape.As best seen in FIGS. 3, 4, 7, 9 and 11, the chain guide 40 has innerand outer (first and second) shifted pivot points P₁ and P₂,respectively, for pivotally securing the derailleur linkage 42 to thechain guide 40. In particular, pivot pins 41 and 43 pivotally couple thechain guide 40 to the derailleur linkage 42. The chain guide 40 has achain receiving slot that is formed by a pair of (inner and outer)vertical shift plates 40 a and 40 b. The vertical shift plates 40 a and40 b are adapted to engage the chain 24, and thus, to move the chain 24in a direction substantially transverse to the bicycle 10. The shiftplates 40 a and 40 b are connected together by a pair of plates 40 c and40 d, i.e. upper and lower plates 40 c and 40 d. The upper plate 40 c isintegrally formed with the inner shift plate 40 a. The lower plate 40 dhas one end that is integrally formed with the outer shift plate 40 band the other end that is attached to the inner shift plate 40 a via afastener, such as a screw or rivet. The upper ends of the shift plates40 a and 40 b are further coupled together by a pair of additionalfasteners, such as a screws or rivets with bushings mounted between theplates 40 a and 40 b in a conventional manner.

Referring now to FIGS. 2-17 and 33-40, the derailleur linkage 42basically includes an inner link 46 and an outer link 48 with first orupper ends pivotally coupled to the fixing body 44 and second or lowerends pivotally coupled to the chain guide 40. Specifically, the innerlink 46 has a first inner link end 46 a pivotally coupled to a fixedinner (first) pivot point P₃ of the fixing body 44 by a pivot pin 47 anda second inner link end 46 b pivotally coupled to the shifted innerpivot point P₁ of the chain guide 40 by the pivot pin 41. Similarly, theouter link 48 has a first outer link end 48 a pivotally coupled to afixed outer (second) pivot point P₄ of the fixing body 44 by a pivot pin49 and a second outer link end 48 b pivotally coupled to the shiftedouter pivot point P₂ of the chain guide 40 by the pivot pin 43.

As apparent from the discussion above, the derailleur linkage 42 ispreferably a four-bar linkage that is formed by the inner link 46, theouter link 48, the portion of the chain guide 40 extending between theinner and outer shifted pivot points P₁ and P₂, and the portion of thefixing body 44 extending between the inner and outer fixed pivot pointsP₃ and P₄. Thus, the pivot axes of the pivot points P₁, P₂, P₃ and P₄are all substantially parallel to each other.

When the derailleur linkage 42 holds the chain guide 40 in its extendedposition, the chain guide 40 is located over the outermost sprocket 26,i.e., the furthest sprocket from the seat tube 16. When the derailleurlinkage 42 holds the chain guide 40 in its retracted position, the chainguide 40 is located over the innermost sprocket 28, i.e., the closetsprocket to the seat tube 16. These movements of the chain guide 40 andthe derailleur linkage 42 are controlled by the electronic shifting unit20, as explained below.

Referring mainly to FIGS. 16 and 17, the outer link 48 includes athreaded hole 48 c that receive a low position adjustment screw 50. Inparticular, the low adjustment screw 50 is arranged and configured tosuch that the free end selectively contacts the fixing body 44 toselectively limit the amount of laterally inward movement of the chainguide 40. Thus, the threaded hole 48 c of the outer link 48, the lowadjustment screw 50 and the fixing body 44 form a part of a mechanicaladjustment device that finely adjusts the low position of the chainguide 40.

Depending on the position of the low adjustment screw 50 relative to theouter link 48 the free end of the low adjustment screw 50 may notcontact the fixing body 44 (e.g. no adjustment if the low adjustmentscrew 50 is unscrewed a predetermined amount) when the chain guide 40 ismoved from the top position to the low position. However, preferably thefree end of the low adjustment screw 50 will selectively contact thefixing body 44 (e.g. if the low adjustment screw 50 is screwed apredetermined amount through the outer link 48) when the chain guide 40is moved from the top position to the low position, as illustratedherein. In other words, once the low adjustment screw 50 is screwed apredetermined amount through the outer link 48, the free end of the lowadjustment screw 50 will contact the fixing body 44 when the chain guide40 is moved from the top position to the low position to limit inwardmovement of the chain guide 40. The contact point can be graduallychanged/adjusted when the low adjustment screw 50 is gradually screwedfurther through the outer link 48.

A top adjustment screw 52 is threadedly coupled to the motor linkage 36to contact the inner link 46 in order to finely adjust the top positionof the chain guide 40. The adjustment of the top position of the chainguide 40 will be discussed in more detail below. The top adjustmentscrew 52 and the portions of the inner link 46 and the motor linkage 36form a part of the mechanical adjustment device that finely adjusts thetop position of the chain guide 40. The top adjustment screw 52 is afirst adjustment screw, while the low adjustment screw 50 is a secondadjustment screw.

Thus, the mechanical adjustment device is configured and arranged tochange the first and second shift positions (e.g. the low and toppositions) of the chain guide 40 relative to the fixing body 44. Inother words, the low adjustment screw 50 is configured and arranged tochange the low shift position of the chain guide 40 relative to thefixing body 44, while the top adjustment screw 52 is configured andarranged to change the top shift position of the chain guide 40 relativeto the fixing body 44. While the adjustment screws 50 and 52 arepreferably mounted on the outer link 48 and the motor linkage 36,respectively, it will be apparent to those skilled in the art from thisdisclosure that the adjustment screws 50 and 52 could be mounted on anyone of the fixing body 44, the chain guide 40, the motor linkage 36 andthe links 46 and 48 with a free end of the respective adjustment screwcontacting any one of the fixing body 44, the chain guide 40, the motorlinkage 36 and the links 46 and 48 to which the adjustment screw is notthreadedly coupled.

In the illustrated embodiment, the top adjustment screw 52 is configuredand arranged to also change the low shift position of the chain guide 40relative to the fixing body 44 when adjusted, if the low adjustmentscrew 50 is not rotated far enough to contact the fixing body 44 whenthe chain guide is moved from the top position to the low position.However, typically, during normal use the low adjustment screw 50 willbe configured to contact the fixing body 44 to limit inward movement ofthe inner and outer links 46 and 48 such that the top adjustment screw52 moves out of contact with the inner link 46 when the chain guide 40is shifted from the top position to the low position as seen in FIGS. 7and 16. In other words, the top adjustment screw 52 is not designed tonormally adjust the low position. In particular, the stroke of the motorunit 34 is configured to move the chain guide 40 over a larger rangethan the lateral spacing between the sprockets 26 and 28 such that theadjustment screws 50 and 52 are used to finely adjust the range ofmovement of the chain guide 40, as explained below in more detail. Eachof the adjustment screws 50 and 52 is also preferably threaded through aplastic washer member (not shown) to prevent accidental looseningthereof.

Referring now to FIGS. 2-13 and 25-28, the motorized front derailleurmounting member 32 basically includes a bicycle frame mounting portion60, a front derailleur mounting portion 62 and a main motor unitmounting portion 64. The bicycle frame mounting portion 60, the frontderailleur mounting portion 62 and the main motor unit mounting portion64 are preferably integrally formed together as a one-piece, unitarymember from a lightweight rigid material by casting, machining or thelike in a conventional manner. Preferably, the front derailleur mountingmember 32 is constructed of a metallic material such as an aluminumalloy, titanium or the like. The front derailleur mounting portion 62and the main motor unit mounting portion 64 form a derailleur motorsupport structure.

The bicycle frame mounting portion 60 is configured and arranged to becoupled to the seat tube 16 of the bicycle frame 14 by the bracket 18using the fasteners 19. The bicycle frame mounting portion 60 includes aprojection 61 that projects outwardly from a first (front) side of themotorized front derailleur mounting member 32 to a free end that forms acurved front surface 61 a with a threaded hole 61 b. The curved frontsurface 61 a is configured and arranged to contact a correspondingcurved portion of the bracket 18 such that the motorized frontderailleur mounting member 32 can not be rotated relative to the bracket18. One of the fasteners or bolts 19 is received through a hole of thebracket 18 and threaded into the threaded hole 61 b of the bicycle framemounting portion 60, while the other two fasteners or bolts 19 arereceived through two other holes of the bracket 18 and threaded into thethreaded holes (only one shown in FIG. 6) formed in the seat tube 16such that the motorized front derailleur mounting member 32 is securedto the bicycle frame 14 via the bracket 18.

The front derailleur mounting portion 62 is configured and arranged tobe coupled to the derailleur linkage 42 of the front derailleur unit 30.In particular, the front derailleur mounting portion 62 has first andsecond inner link supporting parts 62 a and 62 b that are configured andarranged to define an inner link receiving space therebetween forreceiving the inner link 46, and first and second outer link supportparts 62 c and 62 d that are configured and arranged to define an outerlink receiving space therebetween for receiving the outer link 48. Thus,the first and second inner link supporting parts 62 a and 62 b and thefirst and second outer link support parts 62 c and 62 d are configuredand arranged to form the front derailleur fixing body 44. The first andsecond link supporting parts 62 a and 62 b include first and secondinner pivot pin mounting holes 62 e and 62 f, while the first and secondouter link support parts 62 c and 62 d include first and second outerpivot pin mounting holes 62 g and 62 h. The first fixed pivot point P₃is centrally located in the first and second inner pivot pin mountingholes 62 e and 62 f, while the second fixed pivot point P₄ is centrallylocated in the first and second outer pivot pin mounting holes 62 g and62 h. The first and second link supporting parts 62 a and 62 b arespaced differently than the first and second outer link support parts 62c and 62 d to accommodate the different sizes of the inner and outerlinks 46 and 48. The second fixed pivot axis of the second fixed pivotpoint P₄ is substantially parallel to the first fixed pivot axis of thefirst fixed pivot point P₃. The first and second outer link supportparts 62 c and 62 d extend from a connecting section 62 i.

The main motor unit mounting portion 64 is configured and arranged to becoupled to the front derailleur motor unit 34. In particular, the mainmotor unit mounting portion 64 has a first fastener-less matingstructure that includes a motor support surface 66, a holding tab 67, afirst recess 68, a mating projection 69 and a first projection formed bythe first outer link support part 62 c and the connecting section 62 i.The holding tab 67 extends upwardly relative to and is arranged adjacentto the motor support surface 66, while the first recess 68 extendsdownwardly from the motor support surface 66. The mating projection 69extends in a direction parallel to the motor support surface 66 from anend surface of the main motor unit mounting portion 64 below the motorsupport surface 66. The first projection formed by the first outer linksupport part 62 c and the connecting section 62 i extends upwardlyrelative to and is arranged adjacent to the motor support surface 66 ina manner similar to the holding tab 67 (i.e. to form an additionalholding tab opposed to the holding tab 67). In other words, the firstprojection formed by the first outer link support part 62 c and theconnecting section 62 i is located on an opposite lateral side of themotor support surface 66 from the holding tab 67.

The main motor unit mounting portion 64 includes a plurality (two) ofthreaded holes 64 a that form additional mounting parts of the mainmotor unit mounting portion 64, i.e., in addition to the firstfastener-less mating structure. In particular, one of the threaded holes64 a extends through the mating projection 69 into the main motor unitmounting portion 64, while the other threaded hole 64 a extends throughan additional projection that extends rearwardly from an upwardlyextending flange 64 b of the main motor unit mounting portion 64. Theupwardly extending flange 64 b extends upwardly from the rear end of thefirst projection formed by the first outer link support part 62 c andthe connecting section 62 i. The main motor unit mounting portion 64also includes an output shaft support section 64 c with a shaft supporthole 64 d formed therein. The output shaft support section 64 c extendsupwardly from the second outer link support part 62 d. The shaft supporthole 64 d is configured such that it has a center axis that issubstantially parallel to the pivot axes of the first and second fixedpivot points P₃ and P₄ of the front derailleur mounting portion 62. Theshaft support hole 64 d of the main motor unit mounting portion 64 ispreferably a through hole that is completely surrounded by material ofthe main motor unit mounting portion 64 (i.e. enclosed around itsperiphery). A low friction bushing is preferably press-fitted into theshaft support hole 64 d.

Referring now to FIGS. 2-4, 7-13, 18-24, 29-32, 51 and 52, the frontderailleur motor unit 34 basically includes a motor unit casing orhousing 70 and an internal motor structure 72. The internal motorstructure 72 is mounted within the housing 70. The housing 70 of thefront derailleur motor unit 34 is removably mounted to the main motorunit mounting portion 64. Then a motor unit cover 74 is coupled to thehousing 70 and the main motor unit mounting portion 64, as explainedbelow in more detail. The front derailleur motor unit 34 is operativelycoupled the chain guide 40 by the motor linkage 36 and the derailleurlinkage 42. Thus, operation of the front derailleur motor unit 34 by theshifting unit 20 causes the chain guide 40 to be shifted between the lowand top shift positions.

More specifically, an output shaft 80 is rotatably mounted to within thehousing 70 to project out of opposite ends of the housing 70, asexplained below in more detail. The output shaft 80 is operativelycoupled between the internal motor structure 72 and the motor linkage36. The motor unit cover 74 supports one (rear) end of the output shaft80, while the output shaft support section 64 c supports the other(front) end of the output shaft 80 in the low friction bushing that ismounted within the shaft support hole 64 d.

Preferably, the housing 70 includes a first housing part 70 a and asecond housing part 70 b attached to the first housing part 70 a to forman internal cavity for receiving and supporting the internal motorstructure 72 therein, as best seen in FIGS. 18-24, 51 and 52. The firstand second housing parts 70 a and 70 b are constructed as separatemembers from a lightweight rigid material such as plastic by castingand/or machining in a conventional manner. The two housing parts 70 aand 70 b are fixedly attached together via a plurality of (three)fasteners 70 c such as screws and hex nuts. As mentioned above, theoutput shaft 80 extends through opposite ends of the housing 70 (i.e.,through each of housing parts 70 a and 70 b).

As best seen in FIGS. 7, 9-13 and 18-24, 51 and 52, the housing 70 has asecond fastener-less mating structure that includes a lower motorhousing surface 76, an external holding surface 77, a second protrusion78, a flange 79 with a mating hole and a second recess R. The secondfastener-less mating structure is removably coupled to the firstfastener-less mating structure of the main motor unit mounting portion64 without the need for additional fasteners. In particular, the motorhousing surface 76 is supported on the motor support surface 66, theholding tab 67 contacts the external holding surface 77, the secondprotrusion 78 is received in the first recess 68, the flange 79 with themating hole receives the mating projection 69 and the second recess Rreceives the first protrusion formed by the first outer link supportpart 62 c and the connecting section 62 i. The housing 70 furtherincludes another external surface S similar to the external surface 77formed in the recess R that contacts the additional holding tab formedby the second outer link support part 62 d and the connecting section 62i.

The second protrusion 78 has preferably a substantially rectangularconfiguration as viewed along the output shaft 80 and as viewed in sideelevation. The second protrusion 78 is formed of a first protrudingsection 78 a of the first housing part 70 a and a second protrudingsection 78 b of the second housing part 70 b. The second protrusion 78and the mating recess 68 are preferably elongated in a substantiallyparallel direction to the rotation axis of the output shaft 80, with therecess 68 being longer than the protrusion 78. In any case, the firstand second fastener-less mating structures are configured and arrangedto resist rotational movement of the motor unit housing 70 about therotational axis of the output shaft 80 relative to the motorized frontderailleur mounting member 32 due to a torque produced by rotation ofthe output shaft 80 relative to the motor unit housing 70.

Of course, it will be apparent to those skilled in the art from thisdisclosure that one or more of the components of the first and secondfastener-less mating structures (e.g. the motor support surface 66, theholding tab 67, the first recess 68, the mating projection 69, the firstprojection formed by the first outer link support part 62 c and theconnecting section 62 i, the external holding surface 77, the secondprotrusion 78, the flange 79 with a mating hole and the second recess R)may be omitted, modified, reversed and/or substituted for each other ifneeded and/or desired. In any case, the first and second fastener-lessmating structures should be configured to resist rotational torquewithout additional fasteners being essential.

The motor unit cover 74 is a substantially cup-shaped member thatbasically includes a plurality (three) of recesses 74 a, a curvedeccentric pin support slot 74 b, an additional pin support slot 74 c,shaft support bore 74 d and a stopper 74 e, as best seen in FIGS. 29-32.The motor unit cover 74 is preferably constructed as a one-piece,unitary member from a rigid, lightweight material such as a metallicmaterial by casting and/or machining in a conventional manner. Therecesses 74 a are designed to mate with the mating projection 79 and theother two similar projections of the main motor unit mounting portion64. Two of the recesses 74 a have holes formed therethrough forreceiving a pair of fasteners 79 a. The rear end of the output shaft 80is received in the shaft support bore 74 d. The shaft support bore 74 dis preferably a blind bore that has a low coefficient of friction.Optionally, a low friction bushing can be mounted in the shaft supportbore 74 d to rotatably support the output shaft 80. The pin supportslots 74 b and 74 c are configured to support parts of the motorlinkage, as explained below. The stopper 74 e is configured to selectivecontact a part of the motor linkage 36, as also explained below.

In any case, in view of the above structure, the output shaft 80 ispreferably rotatably supported at opposite ends thereof. Because themotor unit cover 74 supports the output shaft 80, the motor unit cover74 is a detachable output shaft support section. Thus, an overall motorunit mounting portion is formed that includes the main motor unitmounting portion 64 and the motor unit cover 74. Accordingly, theoverall motor unit mounting portion includes a pair of spaced outputshaft support sections (e.g. the section 64 c and the cover 74) thatrotatably support opposite ends of the output shaft 80, with at leastone of the output shaft support sections (i.e. the motor unit cover 74)being removably attached to the motorized front derailleur mountingmember 32.

The internal motor structure 72 of front derailleur motor unit 34 ismounted within the housing 70. The internal motor structure 72preferably includes a reversible electric motor that is powered by abattery source or a generator, a drive train including a plurality ofgears operatively coupled between the electric motor and the outputshaft 80, and a position control device that includes various electroniccomponents (e.g. printed circuit board, photo interrupter, top-low brushsensor, etc.) for controlling operation of the electric motor. Theinternal motor structure 72 is electrically coupled to the shifting unit20 by an electrical cord and to a power source (battery source orgenerator) by another electrical cord. Internal motor structures such asthe internal motor structure 72 are well known. Thus, the internal motorstructure 72 will not be discussed or illustrated in detail. Rather, theinternal motor structure 72 can be understood from the second embodimentU.S. patent application Ser. No. 10/787,897, filed on Feb. 27, 2004 andassigned to Shimano, Inc.

Of course, it will be apparent to those skilled in the art from thisdisclosure that minor modifications to the internal motor structure fromthe second embodiment U.S. patent application Ser. No. 10/787,897 may berequired such that it can be supported within the shape of the housing70. However, such modifications are well within the level of ordinaryskill in the art. Accordingly, these structures will not be discussedand/or illustrated in detail herein, except as needed to make and usethe present invention, as defined in the appended claims.

The output shaft 80 is preferably rotatably supported in the housing 70by at least one bearing. Of course, it will be apparent to those skilledin the art from this disclosure that one or more bearings can be mountedon the motorized derailleur mounting member 32 and/or the motor unitcover 74 in addition to or instead of being mounted within the housing70 if needed and/or desired. In any event, the output shaft 80 isconfigured and arranged to rotate in opposite rotational directionsabout a rotational axis A₁ between a first rotational position (i.e. alow shift position orientation as shown in FIGS. 7, 11 and 12) and asecond rotational position (i.e. a top shift position orientation asshown in FIGS. 9, 10 and 13) by rotation of the driving shaft of theinternal motor structure 72.

The output shaft 80 includes an eccentric pin 81 a that has a centeraxis A₂ that is offset from the rotational axis A₁ of the output shaft80. The eccentric pin 81 is mounted to a first end 82 a of a drive arm82. The drive arm 82 has a second end 82 b non-rotatably mounted on therearwardly extending end of the output shaft 80 by a splined connectionor the like. The eccentric pin 81 is rotatably mounted to in a holeformed in the first end 82 a of the drive arm 82. The eccentric pin 81is operatively coupled to the motor linkage 36. Thus, when the outputshaft 80 is rotated, the eccentric pin 81 moves along a circular patharound the rotational axis A₁ of the output shaft 80. When the motorunit cover 74 is mounted to the main motor unit mounting portion 64, therearward end of the eccentric pin 81 is supported in the eccentric pinsupport slot 74 b of the motor unit cover 74. Moreover, when the motorunit cover 74 is mounted to the main motor unit mounting portion 64, thestopper 74 e is arranged to selectively contact the drive arm 82 toprevent further movement thereof.

Referring now to FIGS. 2-15 and 41-50, the motor linkage 36 basicallyincludes a drive or motor link 84, a saver link 86 and a saver linkbiasing element 88. The motor linkage 36 is operatively coupled betweenthe eccentric drive pin 81 of the output shaft 80 and the derailleurlinkage 42. Specifically, the motor linkage 36 is operatively coupledbetween the eccentric drive pin 81 of the output shaft 80 and the innerlink 46 of the derailleur linkage 42. The saver link biasing element 88is operatively coupled between the saver link 86 and the inner link 46.

The inner link 46, the saver link 86 and the saver link biasing element88 form a jamming protection connection between the motor linkage 36 andthe derailleur linkage 42. In particular, part of the inner link 46,part of the saver link 86 and the saver link biasing element 88 form thejamming protection connection. This jamming protection arrangement isconfigured and arranged to move between a force transmitting state and aforce override state. More specifically, the drive link 84 is pivotallymounted to the eccentric pin 81 and the saver link 86, while the saverlink 86 is pivotally coupled to the drive link 84 and the inner link 46.The biasing element 88 is operatively coupled between the inner link 46and the saver link 86 to normally maintain a rigid connection (i.e. anormally rigid state) therebetween, as explained below.

The jamming protection connection arranged between the drive link 84 andthe inner link 46 such that the drive link 84 is permitted to move froman outer shift orientation to an inner shift orientation even if thechain guide 40 is prohibited from moving to the inner shift positionfrom the outer shift position.

The drive link 84 is configured and arranged relative to the outputshaft 80 and the derailleur linkage 42 to shift the chain guide 40 fromthe first (low) shift position to the second (top) shift position, andto the first (low) shift position from the second (top) shift position.The drive link 84 has a first drive link end 84 a and a second drivelink end 84 b. The first drive link end 84 a is rotatably mounted on theeccentric drive pin 81 of the output shaft 80 such that the eccentricdrive pin 81 can rotate within the hole formed in the first drive linkend 84 a. The second drive link end 84 b is pivotally coupled to thesaver link 86 by a pivot pin 85. Thus, when the output shaft 80 isrotated, the drive link 84 is moved or shifted. The first drive link end84 a is preferably retained on the eccentric pin 81 by a C-clip, whilethe second drive link end 84 b is preferably retained on the pivot pin85 by another C-clip. When the motor unit cover 74 is mounted to themain motor unit mounting portion 64, the rearward end of the pivot pin85 is supported in the additional pin support slot 74 c of the motorunit cover 74.

The first drive link end 84 a is operatively coupled to the output shaft80 of the motor unit 34 via the eccentric pin 81 and the drive arm 82.The second drive link end 84 b is operatively coupled to the inner link46 of the front derailleur 30 to move the chain guide 40 from the innershift position to the outer shift position when the first drive link end84 a is pulled in a direction away from the second drive link end 84 b.In other words, the eccentric drive pin 81 is configured to selectivelypull the first drive link end 84 a in the direction away from the seconddrive link end 84 b to shift the chain guide 40 from the inner shiftposition to the outer shift position and to selectively push the firstdrive link end 84 a in a direction toward the second drive link end 84 bto shift the chain guide 40 from the outer shift position to the innershift position.

The drive link 84 has a longitudinal axis L extending between the firstand second drive link ends 84 a and 84 b. The longitudinal axis L of thedrive link 84 has a first orientation (FIG. 7) when the chain guide 40is in the first shift position and a second orientation (FIG. 9) whenthe chain guide 40 is in the second shift position with the first andsecond orientations of the longitudinal axis L of the drive link 84being changed less than forty five degrees between the first and secondorientations, as best seen in FIGS. 7 and 9. The longitudinal axis Lpreferably extends between the centers of the holes formed in the firstand second drive link ends 84 a and 84 b, as best seen in FIG. 45.

The saver link 86 preferably has a first saver link end 86 a, a secondsaver link end 86 b, a control or stop flange 86 c and an abutment tab86 d. The first saver link end 86 a of the saver link 86 is pivotallycoupled to the second drive link end 84 b of the drive link 84 by thepivot pin 85. The pivot pin 85 is preferably press fitted in the hole ofthe first saver link end 86 a, while the pivot pin 85 is rotatablyreceived in the hole of the second drive link end 84 b. The second saverlink end 86 b is operatively coupled to the inner link 46 of thederailleur linkage 42. In particular, the second saver link end 86 bincludes a through hole with the pivot pin 47 extending therethrough anda threaded bore 86 e configured to receive a set screw 86 f. The pivotpin 47 includes a pair of flat surfaces 47 a configured to contact theset screw 86 f to prevent rotation and axial movement of the pivot pin47 relative to the saver link 86. The first inner link end 46 a of theinner link 46 is rotatably mounted on the pivot pin 47.

The control or stop flange 86 c extends from the second saver link end86 b and includes a threaded bore 86 g configured to receive the topadjustment screw 52 therein such that the top adjustment screw 52selectively contacts the inner link 46 when the motor linkage 36 isdriven to the top shift position as best seen in FIGS. 9 and 10. Thus,the top adjustment screw 52 is configured and arranged to change thesecond or top shift position of the chain guide 40 relative to thefixing body 44 by the free end of the top adjustment screw 52 contactingthe inner link 46. The abutment tab 86 d extends axially from a frontside of the control flange 86 c to engage part of the biasing element88.

As best seen in FIGS. 14, 15, 46 and 47, the saver link biasing element88 is preferably a torsion spring having a coiled portion 88 a, a firstleg portion 88 b and a second leg portion 88 c. The coiled portion 88 ais located about a bushing 89 mounted on the pivot pin 47, whichconnects the saver link 86 to the inner link 46. The first leg portion88 b of the saver link biasing element 88 engages the saver link 86,while the second leg portion 88 b contacts the inner link 46 of thederailleur linkage 42. The saver link 86 is biased in a counterclockwisedirection about the pivot point P₃ as viewed from the rear of thederailleur. On the other hand, the inner link 46 is biased in aclockwise direction about the pivot pin 47 as viewed from the rear ofthe derailleur.

Thus, the top adjustment screw 52 is normally biased toward the innerlink 46 to contact the inner link 46, unless the low adjustment screw 50or an obstruction (jam) prevents such contact. In other words, the saverlink biasing element 88 is configured and arranged to apply an urgingforce that normally maintains a substantially rigid connection betweenthe saver link 86 and the derailleur linkage 42 so that these membersnormally move substantially together as a unit, except when the lowadjustment screw 50 limits inward movement of the derailleur linkage 42or when an obstruction limits inward movement. Accordingly, the saverlink 86 is pivotally coupled to the derailleur linkage 42 and the saverlink biasing element 88 is operatively coupled between the saver link 86and the derailleur linkage 42 to urge the saver link 86 from a forceoverride state to the force transmitting state such that a substantiallyrigid connection is normally maintained between the saver link 86 andthe derailleur linkage 42.

Thus, as seen in FIG. 11, if the chain guide 40 is stuck in the topposition, and the motor linkage 36 is driven by the output shaft 80 to alow shift position, the saver link 86 will rotate in a clockwisedirection in about the pivot point P₃ as viewed from the rear of thederailleur against the urging force the first leg portion 88 b of thesaver link biasing element 88 even though the inner link 46 does notmove. Accordingly, a non rigid (jamming protection) connection is formedbetween the saver link 86 and the derailleur linkage 42 by utilizing thesaver link 86 and the saver link biasing element 88. In other words, thesaver link 86 and the saver link biasing element 88 form a non-rigidconnection that connects motor linkage 36 to the derailleur linkage 42.This non-rigid connection forms the jamming protection connection.

Referring again to FIGS. 14 and 15, assembly and operation of thejamming protection connection will be explained in more detail. Inparticular, assembly and operating of the mounting member 32, the innerlink 46, the pivot pin 47, the saver link 86, the biasing element 88 andthe bushing 89 will be explained in more detail. During assembly ofthese parts, the biasing element 88 is mounted on the bushing 89 andplaced adjacent the second saver link end 86 b. The first leg portion 88b of the biasing element is located adjacent the abutment tab 86 d.Next, the first inner link end 46 a is placed with its mounting flangeson opposite ends of the bushing 89 and second saver link end 86 barrangement so that the respective holes are aligned. Next this assemblyis placed between the first and second inner link mounting parts 62 aand 62 b so that all of the holes are aligned. The pivot pin 47 is theninserted through the first inner link mounting hole 62 e, through afirst flange of the inner link 46, through the second saver link end 86b, through the bushing 89 and the biasing element 88, through a secondflange of the inner link 46 and into the second inner link mounting hole62 f. The set screw 86 f is then mounted in the threaded hole 86 e androtated into contact with one of the flat surfaces 47 a. The second legportion 88 c is then moved to engage a tab 46 c of the second inner linkend 46 b of the inner link 46, and assembly is complete. Once the aboveassembly is completely assembled, the assembly is prevented from beingremoved from the motorized front derailleur mounting member 32 eventhough the pivot pin 47 is freely rotatable relative to the mountingmember 32. In other words, the pivot pin 47 is freely rotatable andaxially movable relative to the mounting member 32 until the set screw86 f is installed. Also, the pivot pin 47 is prevented from rotatingrelative to the saver link 86.

The pivot pin 47 is fixed to the saver link 86 due to the arrangement ofthe flat surfaces 47 a and the set screw 86 f, and freely rotatablerelative to the inner link 46 and the motorized front derailleurmounting member 32. Specifically, the pivot pin 47 is rotatably mountedin the first and second inner pivot pin mounting holes 62 e and 62 f ofthe first and second inner link support parts 62 a and 62 b. However,the saver link biasing element 88 is configured and arranged to apply anurging force that normally maintains a rigid connection between thesaver link 86 and the inner link 46 so that these members normally movesubstantially together as a unit. The coiled portion 88 a of the biasingelement 88 is mounted on the bushing 89, which is also rotatably mountedon the pivot pin 47. Thus, the inner link 46, the pivot pin 47 and thebiasing element 88 all normally move together as a unit when the chainguide 40 is shifted between the top and low positions. In other words,the mounting arrangement of the pivot pin 47 provides for reducedfriction when the chain guide 40 is moved between the top and lowpositions. In particular, the ends of the pivot pin 47 are freelyrotatable in the motorized front derailleur mounting member 32 and theinner link 46, while fixed to the saver link 86. Accordingly, the pivotpin 47 moves with the saver link 86 and with the biasing element 88 sothat friction does not occur between the pivot pin 47 and the coiledportion 88 a of the biasing element 88 during movement of the chainguide 40. Moreover, because the inner link 46, the biasing element 88,the saver link 86 and the pivot pin 47 normally move together as a unitwhen the chain guide 40 is moved, no friction normally occurs betweenthe inner link 46 and the pivot pin 47 or between the inner link 46 andthe biasing element 88.

As mentioned above, even though the inner link 46, the biasing element88, the saver link 86 and the pivot pin 47 normally move together as aunit when the chain guide 40 is moved, sometimes the saver link 86 willmove relative to the inner link 46 (i.e. if the chain guide 40 becomesjammed in the top position or when the low adjustment screw 50 contactsthe fixing body 44 when the chain guide 40 is moved to the lowposition). When the saver link 86 is moved relative to the inner link46, friction can also be reduced. In particular, when the saver link 86is moved relative to the inner link 46, the first leg portion 88 b willmove with the saver link 86. Initially, the coiled portion 88 a may alsoadjust its rotational position relative to the bushing 89 (i.e. thecoiled portion 88 a can initially move around the bushing 89). However,after a predetermined amount of movement of the coiled portion 88 a, thecoiled portion 88 a may bind on the bushing 89. Even if the coiledportion 88 a binds on the bushing 89, because the bushing 89 isrotatable relative to the pivot pin 47 the bushing 49 can rotate withthe coiled portion 88 a. In other words, the positions of the coiledportion 88 a and the bushing 89 relative to the first and second legs 88b and 88 c can equalize because the bushing 89 can substantially floaton the pivot pin 47. Because the pivot pin 47 rotates with the saverlink 86, any relative movement between the bushing 89 and the pivot pin47 will be minimized. Due to the above arrangement of the presentinvention, friction can be substantially reduced even when the saverlink 86 moves relative to the inner link 46.

Adjustment of the motorized front derailleur assembly 12 will now beexplained in more detail. The front derailleur unit 30 is mounted to theframe 12 by the motorized front derailleur mounting member 32 andbracket 18. Then the low and top shift positions are set/adjusted byadjusting the low and top adjustment screws 50 and 52. In particular,when the chain guide is in the top shift position so that the chainguide 40 is disposed over the front chain wheel 26, the top adjustmentscrew 52 is rotated until the desired alignment between the chain guide40 and the sprocket 26 is obtained. This adjustment of the top shiftposition causes the relative orientation between the inner link 46 andthe saver link 86 to change. In particular, the adjusting of the topadjustment screw 52 changes the relative orientation between the innerlink 46 and the saver link 86 by counteracting the urging force of thesaver link biasing element 88, i.e., by further compressing the saverlink biasing element 88.

Once the top shift position has been set, the chain guide is shifted tothe low position over the sprocket 28. Then the low shift position isalso adjusted by the adjusting of the low adjustment screw 50 until thedesired alignment between the chain guide 40 and the sprocket 28 isobtained. Thus, the low position is set by using the low adjustmentscrew 50, which contacts the fixing body 44, such that the chain guide40 is disposed over the smaller front chain wheel 28. Of course, becausethe adjusting of the low adjustment screw 52 changes the relativeorientation between the inner link 46 and the saver link 86 this processmay need to be repeated until the desired alignments are obtained. Inother words, after both the top and low positions are adjusted using theadjustment screws 50 and 52, the alignments should be checked. Ofcourse, the low position can be adjusted prior to adjusting the topposition, and then the positions can be checked if needed and/ordesired.

As used herein to describe the present invention, the followingdirectional terms “forward, rearward, above, downward, vertical,horizontal, below and transverse” as well as any other similardirectional terms refer to those directions of a bicycle equipped withthe present invention. Accordingly, these terms, as utilized to describethe present invention should be interpreted relative to a bicycleequipped with the present invention.

In understanding the scope of the present invention, the term“comprising” and its derivatives, as used herein, are intended to beopen ended terms that specify the presence of the stated features,elements, components, groups, integers, and/or steps, but do not excludethe presence of other unstated features, elements, components, groups,integers and/or steps. The foregoing also applies to words havingsimilar meanings such as the terms, “including”, “having” and theirderivatives. Also, the terms “member” or “element” when used in thesingular can have the dual meaning of a single part or a plurality ofparts. Finally, terms of degree such as “substantially”, “about” and“approximately” as used herein mean a reasonable amount of deviation ofthe modified term such that the end result is not significantly changed.These terms of degree should be construed as including a deviation of atleast ±5% of the modified term if this deviation would not negate themeaning of the word it modifies.

While only a selected embodiment has been chosen to illustrate thepresent invention, it will be apparent to those skilled in the art fromthis disclosure that various changes and modifications can be madeherein without departing from the scope of the invention as defined inthe appended claims. Furthermore, the foregoing descriptions of theembodiment according to the present invention are provided forillustration only, and not for the purpose of limiting the invention asdefined by the appended claims and their equivalents.

1. A motorized bicycle front derailleur assembly comprising: a motorunit configured and arranged to rotate an output shaft in a firstrotational direction and a second rotational direction that is oppositethe first rotational direction; a front derailleur including a fixingbody configured to be mounted to a bicycle frame, an inner linkpivotally coupled to the fixing body at a first pivot point, an outerlink pivotally coupled to the fixing body at a second pivot point and achain guide pivotally coupled to the inner and outer links to movebetween an inner shift position and an outer shift position, the firstpivot point being located laterally closer to a center plane of thebicycle frame than the second pivot point; and a motor linkageoperatively coupled to the output shaft of the motor unit and the innerlink of the front derailleur to move the chain guide from the innershift position to the outer shift position upon rotation of the outputshaft in the first rotational direction and to move the chain guide fromthe outer shift position to the inner shift position upon rotation ofthe output shaft in the second rotational direction.
 2. The motorizedbicycle front derailleur assembly according to claim 1, wherein themotor linkage includes a drive link having a first drive link endoperatively coupled to the output shaft of the motor unit and a seconddrive link end operatively coupled to the inner link of the frontderailleur to move the chain guide from the inner shift position to theouter shift position when the first drive link end is pulled in adirection away from the second drive link end.
 3. The motorized bicyclefront derailleur assembly according to claim 2, wherein the output shaftincludes an eccentric drive pin that is offset from a rotational axis ofthe output shaft.
 4. The motorized bicycle front derailleur assemblyaccording to claim 3, wherein the first drive link end of the firstdrive link is pivotally coupled to the eccentric drive pin such that theeccentric drive pin is configured to selectively pull the first drivelink end in the direction away from the second drive link end to shiftthe chain guide from the inner shift position to the outer shiftposition and to selectively push the first drive link end in a directiontoward the second drive link end to shift the chain guide from the outershift position to the inner shift position.
 5. The motorized bicyclefront derailleur assembly according to claim 4, wherein the motorlinkage includes a jamming protection connection arranged between thedrive link and the inner link such that the drive link is permitted tomove from an outer shift orientation to an inner shift orientation evenif the chain guide is prohibited from moving to the inner shift positionfrom the outer shift position.
 6. The motorized bicycle front derailleurassembly according to claim 5, wherein the jamming protection connectionincludes a biasing element configured and arranged to apply an urgingforce that normally maintains the jamming protection connection in anormally rigid state.
 7. The motorized bicycle front derailleur assemblyaccording to claim 6, wherein the jamming protection connection includesa saver link having a first saver link end pivotally coupled to thesecond drive link end and a second saver link end pivotally coupled tothe inner link, and the biasing element is arranged between the saverlink and the inner link to apply the urging force that normallymaintains the saver link and the inner link in the normally rigid state.8. The motorized bicycle front derailleur assembly according to claim 7,wherein the second saver link end is pivotally coupled to the inner linkat the first pivot point.
 9. The motorized bicycle front derailleurassembly according to claim 8, wherein the biasing element is a coilspring mounted on a pivot pin at the first pivot point with a first endof the coil spring engaged with the inner link and a second end of thecoil spring engaged with the saver link.
 10. The motorized bicycle frontderailleur assembly according to claim 7, wherein the front derailleurfurther includes a mechanical adjustment device configured and arrangedto change at least one of the inner and outer shift positions of thechain guide relative to the fixing body.
 11. The motorized bicycle frontderailleur assembly according to claim 10, wherein the mechanicaladjustment device is configured and arranged to change both of the innerand outer shift positions of the chain guide relative to the fixingbody.
 12. The motorized bicycle front derailleur assembly according toclaim 11, wherein the mechanical adjustment device includes a firstadjustment screw configured and arranged to change the outer shiftposition of the chain guide relative to the fixing body.
 13. Themotorized bicycle front derailleur assembly according to claim 12,wherein the first adjustment screw is threadedly coupled to one of theinner link and the saver link, and the first adjustment screw isarranged and configured to contact the other of the inner link and thesaver link to adjust the relative positions of the inner link and thesaver link in order to change the outer shift position of the chainguide relative to the fixing body.
 14. The motorized bicycle frontderailleur assembly according to claim 12, wherein the mechanicaladjustment device further includes a second adjustment screw configuredand arranged to change the inner shift position of the chain guiderelative to the fixing body.
 15. The motorized bicycle front derailleurassembly according to claim 2, wherein the motor linkage includes ajamming protection connection arranged between the drive link and theinner link such that the drive link is permitted to move from an outershift orientation to an inner shift orientation even if the chain guideis prohibited from moving to the inner shift position from the outershift position.
 16. The motorized bicycle front derailleur assemblyaccording to claim 15, wherein the jamming protection connectionincludes a biasing element configured and arranged to apply an urgingforce that normally maintains the jamming protection connection in anormally rigid state.
 17. The motorized bicycle front derailleurassembly according to claim 16, wherein the jamming protectionconnection includes a saver link having a first saver link end pivotallycoupled to the second drive link end and a second saver link endpivotally coupled to the inner link, and the biasing element is arrangedbetween the saver link and the inner link to apply the urging force thatnormally maintains the saver link and the inner link in the normallyrigid state.
 18. The motorized bicycle front derailleur assemblyaccording to claim 17, wherein the saver link is pivotally coupled tothe inner link at the first pivot point, and the biasing element is acoil spring mounted on a pivot pin at the first pivot point with a firstend of the coil spring engaged with the inner link and a second end ofthe coil spring engaged with the saver link.
 19. The motorized bicyclefront derailleur assembly according to claim 18, wherein the pivot pinis non-rotatably coupled to one of the saver link and the inner link,and the pivot pin is rotatably supported by the fixing body.
 20. Themotorized bicycle front derailleur assembly according to claim 17,wherein the front derailleur further includes a mechanical adjustmentdevice having a first adjustment screw configured and arranged to changethe outer shift position of the chain guide relative to the fixing body,and the first adjustment screw is threadedly coupled to one of the innerlink and the saver link, and the first adjustment screw is arranged andconfigured to contact the other of the inner link and the saver link toadjust the relative positions of the inner link and the saver link inorder to change the outer shift position of the chain guide relative tothe fixing body.
 21. The motorized bicycle front derailleur assemblyaccording to claim 16, wherein the inner link is pivotally coupled topart of the motor linkage via a pivot pin that is rotatably supported bythe fixing body and non-rotatably coupled to one of the inner link andthe part of the motor linkage, and the biasing element is a coil springthat is mounted on the pivot pin with a first end engaged with the innerlink and a second end engaged with the part of the motor linkage. 22.The motorized bicycle front derailleur assembly according to claim 2,wherein the front derailleur further includes a mechanical adjustmentdevice configured and arranged to change at least one of the inner andouter shift positions of the chain guide relative to the fixing body.23. The motorized bicycle front derailleur assembly according to claim2, wherein the drive link has a longitudinal axis extending between thefirst and second drive link ends, and the longitudinal axis of the drivelink normally has an outer shift orientation when the chain guide is inthe outer shift position and an inner shift orientation when the chainguide is in the inner shift position with the inner and outerorientations of the longitudinal axis of the drive link being changedless than forty five degrees.